HOWTO Build a Nuclear Devicet

[Eric Cordian]

Dr. Joe Baptista writes:

> Anyone on the planet can make a nuclear device if they have the
> appropriate materials.  The hard part is staying alive due to exposure
> while manufacturing the device.

Why?  Neither U-235 nor Pu-239 is particularly radioactive.  Vitrified
plutonium disks have been used as poker chips by workers in fuel
fabrication facilities.  Most of these materials are only dangerous when
ingested, radiating your tissues with alpha particles directly. They also
have very low rates of spontaneous fission, so neutrons aren't generally a
big deal.

As long as you stay clear of criticality, you aren't going to get radiated
at all.

> Materials

>  4 stainless steal salad bowls (5 - 8 inch diameter)
> 10 pounds of U-235 (Plutonium)
>  1 containment cylinder in which to fit the salad bowls
>  ? some explosives - C4 platic works best - but TNT or gun powder is
>    acceptable.

My bullshit detector is starting to go off.

> 10 pounds of U-235 is required to achive critical mass.

Well, that depends on your moderator, doesn't it?  The "bare sphere"
critical mass of U-235 is over 50 kilograms, if you don't mix it with a
moderator, or surround it with a neutron reflector.  Fast neutron fission
cross-sections aren't particularly large.  Plutonium is somewhat better,
but you'll need at least 11 kilograms, even with a nice tamper to bounce
the neutrons back.

> However less will work but you will get a sub critical mass on
> detonation.  The difference is taking out an entire city as opposed to a
> few city blocks.

A sub-critical mass won't do squat.  A criticality accident will kill you,
and require a hazmat crew to clean up your lab, but it won't blow anything
up.  Generally, what you make critical will just melt and splatter into a
non-critical shape, if no effort is made to confine it.

> Divide the U-235 into two five pound masses.  Beat it evenly into the 
> inside of one of your salad bowls.  U-235 is malleable like gold so you
> should have no problem shaping it.  Do the same with the other U-235 mass
> and shape it into the other salad bowl.

This is silly.  Nuclear weapons can be made to work by compressing a solid
sphere to double density with explosives, or by removing an "apple core"
third of a supercritical sphere, and shooting it back in with a gun.  The
hollow sphere myth remains pervasive because scientists had the idea of
imploding a hollow sphere with explosives when the Manhattan project
begun, and because the government has been less than forthcoming with what
methods actually turned out to work.

While a generous hollow sphere with a small void might work, something
made by beating nuclear material into a salad bowl certainly wouldn't,
even if you managed to time the explosives perfectly.

I suggest you look uranium up in your materials handbook before you start
whacking it into your salad bowl.  Pure uranium is only slightly softer
than steel, and with a little molybdenum added, is harder than the finest
tool steel.  Malleable means the material doesn't break when you work
it.  It is not a measure of how much force is required to work it.  Gold
is soft.  Uranium isn't.

> Keep the two bowls apart - you don't want an accident to cause your
> project to go critical.

Did Jack Lemmon write this laughable tract back during his "China
Syndrome" days?

> C4 explosives work best.  You simply mold the C4 into the other two salad
> bowls.  This is the most dangerous part of the project.  Improper handling
> of C4 can cause an explosion.  But gun powder is just as effective.

I think you need to look up "velocity of detonation" as it pertains to gun
powder.

> Now fit the U-235 salad bowls into the C4 salad bowls and place them at
> each end of the cylindrical containment.  Connect your explosives to a
> detonator and close off the ends of the cylynder.  Make sure the detonator
> sets off both explosives at the same time.

> The trick is to bring the U-235 masses together at the same time.

Uh huh.

> And thats it.  I would recommend some form of protection while building
> the project.  The aprons worn by dentists will work.  They will protect
> you to some degree from radioactive poisoning.  However - your life is
> only being prolonged by taking such measures - you still will end up dead
> due to the U-235 radiation regardless of what you do.

U-235 radiation?  This person would flunk even the elementary school
course in nuclear engineering.  Clad unirradiated nuclear fuel can be
safely handled without protective clothing, and isn't particularly
radioactive.

> Anyone on this planet can build a nuclear device.  So the only issue in
> building the device is the will to die for a cause.  And the only thing I
> find unfortunate in all of this is that there are so many causes that
> people are willing to die for.  And war will not make those reasons go
> away - it will only encourage them.

Well, anyone with a few minor mechanical engineering clues, a calculator,
and the ability to calculate fission cross-sections.

Dying isn't required, unless you stand near the bomb when it goes off.

-- 
Eric Michael Cordian 0+
O:.T:.O:. Mathematical Munitions Division
"Do What Thou Wilt Shall Be The Whole Of The Law"